Polarity and Dipoles

Electronegativity

The attractive force on electrons by atoms.

Ionic bond

A type of bond formed between a metal and a nonmetal.

Covalent bond

A type of bond formed between two nonmetals.

Electronegativity difference for ionic bonds

Differential of 1.8 - 4.0.

Electronegativity difference for covalent bonds

Differential of 0.0 - 1.8.

Nonpolar covalent bond

A bond with an electronegativity difference of 0.0 - 0.4.

Polar covalent bond

A bond with an electronegativity difference of 0.4 - 1.8.

Polar bond

A bond with a significant overall difference in electronegativity creating a positive and negative side.

δ+ (Delta positive)

Indicates the side where electrons move away from.

δ- (Delta negative)

Indicates the side where electrons are closer to.

Nonpolar bond

A bond where the electronegativity difference is 0 or close to zero, leading to equal sharing of electrons.

Bond polarity

Determined by the electronegativity difference between two atoms.

Molecular polarity

Refers to the overall polarity of a molecule, influenced by symmetrical or asymmetrical arrangements.

Symmetrical molecules

Are typically nonpolar.

Asymmetrical molecules

Are typically polar.

Bond strength

In ionic bonds, it is determined by the large differences in electronegativity.

Electron sharing in covalent bonds

Occurs when there is little to no electronegativity difference.

Ionic character of a bond

Increases with a greater electronegativity difference.

Covalent character of a bond

Present when the electronegativity difference is small.

Polarity of molecules

Depends on both bond polarity and molecular symmetry.

Electronegativity trends

Increases across a period and decreases down a group in the periodic table.